Wireless communication has become ubiquitous in our society. For instance, 5G, which is the marketing term for the upcoming wireless standard for mobile technologies such as cell phones, promises even faster communication speeds and consequently increasing the amount of information being transmitted wirelessly. To provide these faster speeds, 5G plans to expand its frequency range to the higher bands, e.g., at 26 GHz and above. In addition to cell phones, devices such as automobiles, watches, home appliances, medical devices, etc., now include wireless communication capabilities. To provide wireless communication capabilities, devices must be fitted with appropriate antennas that transmit and/or receive wireless signals at the desired frequency range. Designing those antennas to the desired frequency and performance parameters and obtaining the desired radiation pattern is paramount for effective communication.
In most cases, antennas are tested in anechoic chambers. FIG. 1 illustrates a conventional anechoic chamber 100, which is essentially a large room with RF absorbers 102 on the walls to reduce interference signals. An antenna under test (AUT) 103 will be placed in the chamber along with a measuring or probe antenna. Anechoic chambers suffer from several drawbacks, however. First, they are expensive to construct and maintain due to the fragility of the absorbers. Second, because of the size of the anechoic chambers, they are not transportable to measure antennas in different locations in the supply line, such as the manufacturing plant. Third, conventional large-scale anechoic chambers are not appropriate for measuring radiation patterns for high frequency antennas because the cables from the measuring instruments placed outside the chamber need to be connected to the antennas (the AUT and the measuring antenna) placed inside the chamber. At frequencies above 30 GHz, the attenuation of the signal in long cables reduces the signal to noise ratio considerably, i.e., the signal becomes too weak for effective measurements.
If the AUT is electrically large, to reduce the size of the anechoic chamber, compact ranges may be used. However, compact ranges are also very expensive to construct and maintain, and suffer from the same drawbacks as anechoic chambers.
Accordingly, the inventor recognized a need in the art for an antenna characterization system that provides accurate measurements for broader frequency ranges while also being compact, transportable, and easy to set up.